Compound helicopter

Abstract

A compound helicopter includes a fuselage, a fixed wing, a rotary wing, and a barrier member. The fixed wing is fixed to the fuselage. The rotary wing is rotatably coupled to the fuselage. The barrier member is attached to a part, of the fuselage, that is above the fixed wing and is between the rotary wing and the fixed wing. The barrier member is configured to generate no lift upon forward flight.

The invention claimed is: 
     
       1. A compound helicopter comprising:
 a fuselage; 
 a fixed wing fixed to the fuselage; 
 a rotary wing rotatably coupled to the fuselage; and 
 a barrier member attached to a part, of the fuselage, that is above the fixed wing and is between the rotary wing and the fixed wing, 
 wherein at least a part of a lower surface of the barrier member is facing an upper surface of the fixed wing and is exposed to an upwash from the fixed wing during forward flight of the compound helicopter, 
 wherein at least a part of an upper surface of the barrier member is exposed to a downwash from the rotary wing during the forward flight of the compound helicopter, 
 wherein the barrier member includes a front end, a rear end, and a cross-section that is symmetrical about a plane coupling the front end and the rear end to each other, and 
 wherein, upon a forward flight at a predetermined speed, an angle of attack of the barrier member is zero degrees. 
 
     
     
       2. The compound helicopter according to  claim 1 , wherein the barrier member is swingably attached to the fuselage to allow the plane to be oriented horizontally upon the forward flight at the predetermined speed. 
     
     
       3. The compound helicopter according to  claim 1 , wherein the barrier member includes a tip that is coupled to a wing tip of the fixed wing. 
     
     
       4. The compound helicopter according to  claim 1 , wherein the barrier member blocks at least a part of the downwash from the rotary wing to reach the upper surface of the fixed wing during the forward flight of the compound helicopter. 
     
     
       5. The compound helicopter according to  claim 1 , wherein the barrier member is disposed in a downwash of the rotary wing and an upwash from the fixed wing. 
     
     
       6. The compound helicopter according to  claim 1 , wherein the barrier member is rotated based on a flight condition such that the barrier member is oriented horizontally during flight. 
     
     
       7. The compound helicopter according to  claim 1 , wherein the barrier member is swingably attached to the fuselage to maintain the angle of attack of zero degrees of the barrier member during flight of the compound helicopter. 
     
     
       8. The compound helicopter according to  claim 1 , wherein upon the forward flight at the predetermined speed, the fuselage is tilted forward. 
     
     
       9. The compound helicopter according to  claim 8 , wherein the barrier member is swingably attached to the fuselage to maintain the angle of attack of zero degrees of the barrier member during flight of the compound helicopter. 
     
     
       10. The compound helicopter according to  claim 1 , wherein, upon a forward flight at a predetermined speed, an angle of attack of the barrier member is substantially zero degrees. 
     
     
       11. A compound helicopter comprising:
 a fuselage; 
 a fixed wing fixed to the fuselage; 
 a rotary wing rotatably coupled to the fuselage; and 
 a barrier member attached to a part, of the fuselage, that is above the fixed wing and is between the rotary wing and the fixed wing, 
 wherein the barrier member includes a front end, a rear end, and a cross-section that is symmetrical about a plane coupling the front end and the rear end to each other, and 
 wherein, upon a forward flight at a predetermined speed, an angle of attack of the barrier member is zero degrees. 
 
     
     
       12. The compound helicopter according to  claim 11 , wherein the barrier member blocks at least a part of a downwash from the rotary wing to reach an upper surface of the fixed wing during forward flight of the compound helicopter. 
     
     
       13. The compound helicopter according to  claim 11 , wherein upon the forward flight at the predetermined speed, the fuselage is tilted forward. 
     
     
       14. The compound helicopter according to  claim 13 , wherein the barrier member is swingably attached to the fuselage to maintain the angle of attack of zero degrees of the barrier member during flight of the compound helicopter. 
     
     
       15. The compound helicopter according to  claim 11 , wherein, upon a forward flight at a predetermined speed, an angle of attack of the barrier member is substantially zero degrees. 
     
     
       16. A compound helicopter comprising:
 a fuselage; 
 a fixed wing fixed to the fuselage; 
 a rotary wing rotatably coupled to the fuselage; and 
 a barrier member attached to a part, of the fuselage, 
 wherein the barrier member is disposed in a downwash of the rotary wing and an upwash from the fixed wing, 
 wherein the barrier member includes a front end, a rear end, and a cross-section that is symmetrical about a plane coupling the front end and the rear end to each other, 
 wherein upon a forward flight at a predetermined speed, the fuselage is tilted forward, and 
 wherein upon the forward flight at the predetermined speed, an angle of attack of the barrier member is zero degrees. 
 
     
     
       17. The compound helicopter according to  claim 16 , wherein the barrier member blocks at least a part of the downwash from the rotary wing to reach an upper surface of the fixed wing during forward flight of the compound helicopter. 
     
     
       18. The compound helicopter according to  claim 16 , wherein the barrier member is swingably attached to the fuselage to maintain the angle of attack of zero degrees of the barrier member during flight of the compound helicopter. 
     
     
       19. The compound helicopter according to  claim 16 , wherein, upon a forward flight at a predetermined speed, an angle of attack of the barrier member is substantially zero degrees.